The switches ground the window motor, so likely you have a broken wire in the flex boot at the door opening.

Check to see if the wires ground when the switch is operated, then see if they are both hot with the swtich neutral, ignition on.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!